Impact on Jupiter

Space telescope Hubble has photographed the results of the collision of an asteroid or a comet with the gas giant.

 

La planète Jupiter photographiée par le télescope spatial Hubble le 23 juillet dernier. Zone agrandie : la trace sombre d’environ 7 000 km de large laissée par l’impact d’un astéroïde ou d’une comète. Credit: NASA, ESA and H. Hammel (Space Science Institute, Boulder, Colorado) and the Jupiter Comet Impact Team

On 19 July 2009, amateur Australian astronomer Anthony Wesley noticed an unusual black spot on Jupiter. Once informed, the professional observatories turned towards the largest planet in the solar system. Their verdict: Jupiter’s turbulent weather (600 km/h winds in the outer layers) cannot be responsible for this dark spot which is reminiscent of a famous precedent, namely a collision with comet Shoemaker-Levy 9 in July 1994.

Asteroid or comet?
15 years ago, this comet disintegrated into several pieces as it approached Jupiter. The fragments falling on to the gas giant created dark blemishes in Jupiter’s atmosphere which lasted a few months, bearing witness to the violence released during such collisions. It was calculated that the biggest impact, that of comet Shoemaker-Levy 9 fragment G, released power equal to 600 times the explosion of our planet’s entire military nuclear arsenal!

Un des impacts causés par la comète Shoemaker-Levy 9 en 1994. Crédit : NASA

But this time, contrary to 1994, astronomers did not see the object involved in the collision beforehand. However, by analysing the images collected by different telescopes, scientists estimate that it was a comet or an asteroid — without being able to decide between the two — several hundreds of metres wide.
On 23 July, space telescope Hubble joined in the observation campaign by photographing Jupiter and obtaining the sharpest image in the visible light range. The “scar” left by the impact measured approx. 7,000 km at its widest point. Hubble took this photograph using its brand new WFC3 camera (Wide Field Camera 3) which was installed during the space shuttle STS-125 mission last May. It should be noted that the instrument checkout and calibration phase is not yet finished. But, given the importance of the event, the teams responsible for the orbital observatory decided to interrupt the schedule and they have no regrets as, according to astronomer Heidi Hammel from the Space Science Institute in Boulder, Colorado, Hubble’s data, combined with that obtained by the ground telescopes, should make it possible to have a better understanding of what happened.

The space shuttle STS-125 mission on Enjoy Space: article and portfolio

Enjoy Space portfolio of Hubble’s most beautiful photographs

Published on 27 July 2009